Carbon Trapping Termites

NOVEMBER 13, 2023

They’re a property owner’s worst nightmare, but are some termites secretly slowing climate change?

Professor Daniel Breecker and graduate student Morgan Mellum of the Department of Earth and Planetary Sciences are wiring termite mounds in South Africa with sensors to find out.

Funded by the National Science Foundation, the study is the first stage of a three-year pilot project to gather data on how termites store carbon dioxide (CO₂₎ underground.

Breecker said the research could be useful for conservationists and policymakers who want to tackle climate change while protecting native species.

“We need to know the rates of CO₂ removal from the atmosphere because the carbon credits associated with it in the mounds may actually be more profitable to local farmers than growing wheat,” he said.

Termite mounds are ubiquitous across South Africa. Their presence can shape the landscape, with some mounds persisting for thousands of years. Importantly, most also accumulate calcium carbonate, a chalky substance found in soil, limestone and shells. Breecker and Mellum said that microbes in the mounds might be the reason.

The researchers think that when the termites carry fallen leaves from certain plants back to their mounds, microbes convert the carbon stored in leaves into calcium carbonate, locking it away in the ground. The sensors will tell them how much CO₂ is ending up in the soil, and, importantly, whether it originated from the air originally taken up by the plant leaves or somewhere else.

The CO₂ path from leaves to termites to soil may not be unique to South Africa. Breecker plans to investigate the Sonoran Desert of the southwestern United States, where the saguaro cactus also stores CO₂.

“Half the world’s soil is rich in calcium carbonate, but there’s not much work explaining why,” he said. “We need to know what’s driving it and how much of it is sequestering atmospheric CO₂.”

The termite mound project includes researchers from the Jackson School of Geosciences, Kent State University and Desert Botanical Garden in the U.S.; and Stellenbosch University, University of Pretoria and Nelson Mandela University in South Africa.